Derive the formula of the heat energy produced in the conductor because of electric current flows in it for the relax time-interval .t.. Give its unit.

Derive the formula of the heat energy produced in the conductor becaus

1.	Derive the formula of the heat energy produced in the conductor because of electric current flows in it for the relax time-interval .t.. Give its unit.
Answer» Solution :A metallic conductor (or a resistance wire) offers resistance to the FLOW of current, so work must be done by the current-source for a continuous flow of electric current through a conductor. Consider a current I flowing through a resistor (or conductor) of resistance R. Let V be the potential difference across the resistor (see figure). Let t be the time-interval during which a charge Q flows through the resistor (conductor). The work done by the current source in moving charge Q through a potential difference V is vg. THEREFORE, the current source must supply energy to the circuit equal to VQ in time t. Thus, energy spent by the source or thework done by the source, `W = VQ` `= V ("It") ( :. I = Q/t)` `=(IR) ("It")` (By the Ohm.s law V =IR) `:. W = I^2Rt... ....(12.15)` This electrical energy gets dissipated as heat in the resistor. Thus for a steady current I, the AMOUNT of heat H generated (produced) in time- interval t is `H = I^2 Rt`.......(12.16) This is known as the Joule.s law of heating. The SI unit of electrical energy and heat energy is the joule (J). Its other UNITS are watt-second (Ws) and kilowatt-hour (kWh) or unit (commercialunit for electrical energy).